Conferences - Seminars

  Monday 12 March 2018 13:15 - 14:15 MXF 1

Atomic scale investigation of two dimensional materials using transmission electron microscopy

By Dr Hanako OKUNO, CEA-Grenoble, France

Two dimensional (2D) layered structures, such as graphene and transition metal dichalcogenides (TMDs), have attracted much attention for future electronics and optoelectronics due to their unique electronic structures. The properties of 2D materials are strongly influenced by their atomic structures. Visualizing their structural and chemical configuration at atomic scale is thus essential to understand and further control these atomically thin materials. Recently a low-voltage aberration corrected transmission electron microscopy (LVAC-TEM) has been intensively developed and recognized as the most powerful technique giving an atomic scale imaging of one or few atom thick layer materials, which provides precise local structural information such as vacancies and dislocations. In addition, this technique also allows to modify the atomic structure in 2D layers by electron irradiation. Therefore, we are able to follow atom displacements during the defect formation to study their dynamics. In this talk, LVAC-TEM characterization techniques for the study of 2D materials concerning their defects, strain, dopants and further dynamics will be demonstrated and how these structural analysis can contribute to the domain of 2D engineering will be discussed.
A novel 2-step-ALD route to ultra-thin MoS2 films on SiO2 through a surface organometallic intermediate, S. Xadot, O. Renault; M. Fregnaux, D. Rouchon, E. Nolot, K. Szeto, C. Thieuleux, L. Veyre, H. Okuno, F. Martin and A. Quadrelli, Nanoscale 9, 538 (2017)
CVD graphene recrystallization as a new route to tune graphene structure and properties, A. V. Tyrnina, H. Okuno, P. Pochet, J. Dijon, Carbon 102 (1) 499-505 (2016)
Structural evolution of dilute magnetic (Sn, Mn)Se films grown by molecular beam epitaxy, V. Kanzyuba, S. Dong, X. Liu, X. Li, S. Rouvimov, H. Okuno, H. Mariette, X. Zhang, S. Ptasinska, B. D. Tracy, D. J. Smith, M. Dobrowolska and J. Furdyna, J. Appl. Phys. 121, 075301 (2017)
Bio: Hanako OKUNO graduated with a Master Degree in Materials Science and engineering from Tokyo Institute of Technology in 1999. She received PhD in Materials Science from Louvain catholic University in Belgium, entitled “Synthesis and characterization of carbon based materials” in 2006. She worked in advanced microscopy to develop quantitative chemical atomic resolution imaging on semiconductor during her post-doc fellows at NIMS in Japan and CEA in France and then joined CEA LITEN in 2009 where she worked on the integration of CNTs in microelectronic device applications. Since 2012, she has been working in Laboratory of advanced electron microscopy in CEA INA, whereas she specializes advanced microscopy for two-dimensional material study using low-voltage aberration corrected TEM techniques.

Organization Esther Amstad & Vaso Tileli

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